CN108133900A - A kind of Defect Scanning board and its automatic defect classification method - Google Patents

Abstract

The invention discloses a defect scanning machine and its automatic defect classification method. The defect scanning machine includes: a GDS database establishment unit, which is used to join the GDS database, and define different areas in the database, and define different types of defects according to different areas The defect scanning unit is used to scan the target wafer to capture defects; the defect comparison unit is used to compare the captured defects in the GDS database in real time during the scanning process; the defect classification unit is based on the defect ratio The comparison result of the unit determines the area where the defect is located, and then determines the defect type of the corresponding area according to the pre-definition to realize automatic classification of defects. The present invention realizes automatic classification of fatal defects and non-fatal defects.

Description

A defect scanning machine and its automatic defect classification method

technical field

The invention relates to the technical field of semiconductor manufacturing, in particular to a defect scanning machine and an automatic defect classification method thereof.

Background technique

The advanced integrated circuit manufacturing process generally includes hundreds of steps, and a small error in any link will lead to the failure of the entire chip, especially as the critical size of the circuit continues to shrink, its requirements for process control are becoming more and more stringent, so In order to find and solve problems in time during the production process, it is generally necessary to carry out online defect detection on products.

At present, the mainstream defect detection equipment in the industry is divided into dark field scanning, bright field scanning, electronic scanning, etc., which mainly rely on various scanning machines to scan, and then take images of the scanned defects through visual inspection machines. Machines can be classified according to size, defect signal strength, etc. to distinguish different types of defects. However, there is no one in the industry that can effectively realize killer defects and non-killer defects. defect) automatic classification defect scanning machine, therefore, it is necessary to propose a technical means to solve the above problems.

Contents of the invention

In order to overcome the shortcomings of the above-mentioned prior art, the object of the present invention is to provide a defect scanning machine and its automatic defect classification method, so as to realize the automatic classification of fatal defects and non-fatal defects.

In order to achieve the above and other purposes, the present invention proposes a defect scanning machine, including:

The GDS database establishment unit is used to join the GDS database, define different areas in the database, and define different types of defects according to different areas;

a defect scanning unit for scanning the target wafer to capture defects;

A defect comparison unit is used to compare the captured defects with the GDS database in real time during the scanning process;

The defect classification unit determines the region where the defect is located according to the comparison result of the defect comparison unit, and then determines the defect type of the corresponding region according to the predefined definition to realize the automatic classification of the defect.

Further, the GDS database building unit defines a killer area and an ISO area in the database, defines the defects in the killer area as fatal defects, and defines the defects in the ISO area as non-fatal defects.

Further, the GDS database building unit defines the graphics area as a killer area and the non-graphics area as an ISO area by means of scanning or coordinate setting.

Further, the defect classification unit determines whether the current defect is in the killer area or the ISO area according to the comparison result of the defect comparison unit, and determines whether the current defect is a fatal defect or a non-fatal defect according to the defect definition of the killer area and the ISO area in advance .

Further, the defect classification unit generates and outputs a defect report according to the classification result.

In order to achieve the above object, the present invention also provides a defect automatic classification method for a defect scanning machine, comprising the following steps:

Step 1. Add the GDS database to the defect scanning machine system of the defect scanning machine, and define different areas in the database, and define different types of defects according to different areas;

Step 2. Scan the target wafer to capture defects

Step 3, comparing the captured defects with the GDS database in real time during the scanning process;

Step 4: Determine the region where the defect is located according to the comparison result in Step 3, and then determine the defect type of the corresponding region according to the predefined definition to realize the automatic classification of the defect.

Further, in step 1, a killer area and an ISO area are defined in the GDS database, and the defects in the killer area are defined as fatal defects, and the defects in the ISO area are defined as non-fatal defects.

Further, in step 1, the graphics area is defined as the killer area and the non-graphics area is defined as the ISO area by means of scanning or coordinate setting.

Further, in step 4, it is determined whether the current defect is in the killer area or the ISO area according to the comparison result of step 3, and whether the current defect is a fatal defect or a non-fatal defect is determined according to the defect definition of the killer area and the ISO area in advance.

Further, in step 4, a defect report is also generated and output according to the classification result.

Compared with the prior art, the defect scanning machine and its defect automatic classification method of the present invention add the GDS database to the defect scanning machine system, and define the graphic area in the form of graphic scanning or coordinate setting in the database. It is the killer area, the non-graphic area is defined as the ISO area, and the defects in the corresponding area are defined. During the scanning process, the captured defects are compared with the GDS database in real time to determine whether the defect is in the killer area or the ISO area, and according to the pre-defined location of the defect The defects are classified according to the region, and the purpose of automatic classification of fatal defects and non-fatal defects is realized.

Description of drawings

Fig. 1 is a schematic diagram of the system structure of a defect scanning machine of the present invention;

Fig. 2 is a flow chart of the steps of an automatic defect classification method for a defect scanning machine according to the present invention;

3 is a schematic diagram of the architecture of defect scanning in a specific embodiment of the present invention;

Fig. 4 is the definition diagram of GDS database in the specific embodiment of the present invention;

Fig. 5 is a schematic diagram of automatic classification of graphic process defects in a specific embodiment of the present invention;

6 is a schematic diagram of pre-classification of non-graphic process defects in a specific embodiment of the present invention;

Fig. 7 is a defect report diagram without GDS database analysis and the present invention with GDS database analysis.

Detailed ways

The implementation of the present invention is described below through specific examples and in conjunction with the accompanying drawings, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific examples, and various modifications and changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

FIG. 1 is a schematic diagram of the system structure of a defect scanning machine according to the present invention. As shown in FIG. 1 , a defect scanning machine of the present invention includes: a GDS database establishment unit 101 , a defect scanning unit 102 , a defect comparison unit 103 and a defect classification unit 104 .

GDS (Graphic Design System, graphic design system) database establishment unit 101, is used for adding GDS database, defines killer area and ISO area in database, defines fatal defect (killer defect) with the defect of killer area, defines the defect of ISO area It is a non-killer defect. Specifically, the GDS (Graphic Design System, Graphic Design System) database building unit 101 adds GDS database information to the defect scanning machine system, and defines the killer area and ISO area in the database, for example, by scanning or coordinate setting. The graphics area is defined as a killer area, the non-graphics area is defined as an ISO area, and the defects in the killer area are defined as fatal defects, and the defects in the ISO area are defined as non-killer defects.

The defect scanning unit 102 is configured to scan a target wafer (wafer) to capture defects. In a specific embodiment of the present invention, the defect scanning unit 102 can scan the target wafer (wafer) by means of dark field scanning, bright field scanning, or electronic scanning, and obtain the coordinate position of the defect when a defect is captured. However, the present invention is not limited thereto, and since the specific defect scanning method used is the prior art, it will not be described in detail here.

The defect comparison unit 103 is used for comparing the captured defects with the GDS database in real time during the scanning process. Specifically, the defect comparing unit 103 will compare the captured coordinate position of the defect with the corresponding coordinate position in the GDS database, so as to confirm the area where the defect is located. Of course, the defect comparison unit 103 can also confirm the region where the defect is located through pattern comparison, and the present invention is not limited thereto.

The defect classification unit 104 determines the region where the defect is located according to the comparison result of the defect comparison unit 103 , and further determines the defect type of the corresponding region according to the predefined definition. Specifically, the defect classification unit 104 determines whether the current defect is in the killer area or the ISO area according to the comparison result of the defect comparison unit 103, and determines whether the current defect is a fatal defect (killer defect) according to the defect definition of the killer area and the ISO area in advance. It is still a non-killer defect, and the automatic classification result is output, that is, if the current defect is in the killer area, it is classified as a fatal defect, and if the current defect is in the ISO area, it is classified as a non-killer defect.

FIG. 2 is a flow chart of the steps of an automatic defect classification method for a defect scanning machine according to the present invention. As shown in Figure 2, a defect automatic classification method for a defect scanning machine of the present invention includes the following steps:

Step 201, add the GDS database to the defect scanning machine system of the defect scanning machine, define the killer area and the ISO area in the database, define the defect in the killer area as a fatal defect (killer defect), and define the defect in the ISO area as non- Fatal flaw (non-killer defect). Add GDS database information to the defect scanning machine system, and define the killer area and ISO area in the database, for example, define the graphics area as the killer area and the non-graphics area as the ISO area through scanning or coordinate setting, and then Defects in the killer area are defined as fatal defects, and defects in the ISO area are defined as non-killer defects.

In step 202, the target wafer is scanned to capture defects. In a specific embodiment of the present invention, the target wafer (wafer) can be scanned by means of dark field scanning, bright field scanning, or electronic scanning, and when a defect is captured, the coordinate position of the defect can be obtained. The defect scanning method is a prior art, so it will not be repeated here.

Step 203, comparing the captured defects with the GDS database in real time during the scanning process. Specifically, in step 203, the coordinate position of the captured defect will be compared with the corresponding coordinate position in the GDS database, so as to confirm the area where the defect is located. Of course, the present invention can also confirm the location of the defect through graphic comparison. area, the present invention is not limited thereto.

In step 204, the region where the defect is located is determined according to the comparison result in step 203, and then the defect type of the corresponding region is determined according to a predefined definition. Specifically, determine whether the current defect is in the killer area or the ISO area according to the comparison result of the defect comparison, and determine whether the current defect is a killer defect (killer defect) or a non-fatal defect (non-fatal defect) according to the defect definition of the killer area and the ISO area in advance. -killer defect), and output the automatic classification result, that is, if the current defect is in the killer area, it will be classified as a fatal defect, and if the current defect is in the ISO area, it will be classified as a non-fatal defect.

FIG. 3 is a schematic diagram of the structure of defect scanning in a specific embodiment of the present invention. 1 is the defect scanning part, 2 is the GDS database, and 3 is the operation interface. The GDS database defines the graphic area as the killer area through graphic scanning or coordinate setting, and defines the non-graphical area as the ISO area, as shown in Figure 4. When the defect scanning unit 102 scans the target wafer (wafer) to capture defects, the defect comparison unit will compare the captured defects with the GDS database in real time, and if the defect is in the killer area of the graphics process, it will be automatically classified as a fatal defect ( killer defect), if the defect is in the ISO area of the graphics process, it will be automatically classified as a non-killer defect, as shown in Figure 5. For non-graphics process, it can be matched with any existing graphic process GDS data, as shown in Figure 6, which can realize the pre-classification of non-graphics process defects, predict potential killer defects in advance, and realize the failure of fatal defects in advance Data analysis of killer defect fail ratio.

Fig. 6 is a diagram of a defect report without GDS database analysis and the present invention with GDS database analysis. It can be seen that the present invention realizes the purpose of automatic classification of fatal defects and non-fatal defects by adopting GDS database analysis.

To sum up, a defect scanning machine and its defect automatic classification method in the present invention add the GDS database to the defect scanning machine system, and define the graphic area as the killer in the form of graphic scanning or coordinate setting in the database. Area, the non-graphic area is defined as the ISO area, and the defects in the corresponding area are defined. During the scanning process, the captured defects are compared with the GDS database in real time, and the defect is determined to be in the killer area or the ISO area. The defects are classified to achieve the purpose of automatic classification of fatal defects and non-fatal defects.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Any person skilled in the art can modify and change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be listed in the claims.

Claims (10)

1. a kind of Defect Scanning board, including：

GDS database establishes unit, for adding in GDS database, and the different zones defined in database, according to different zones Define different type defect；

Defect Scanning unit, for scanning target wafer to capture defect；

Defect comparing unit, for that will be captured in real time in scanning process the defects of, are compared in the GDS database；

Defect taxon, the region according to residing for the comparison result of the defect comparing unit determines defect, and then according to advance The defects of determining corresponding region type is defined to realize the automatic classification of defect.

2. a kind of Defect Scanning board as described in claim 1, it is characterised in that：The GDS database establishes unit in number Critical defect is defined according to killer regions defined in library and ISO regions, and by the defects of killer regions, by lacking for ISO regions It falls into and is defined as non-lethal defect.

3. a kind of Defect Scanning board as claimed in claim 2, it is characterised in that：The GDS database is established unit and is passed through Graphics field is defined as killer regions by the form of scanning or setting coordinate, and non-graphic region is defined as ISO regions.

4. a kind of Defect Scanning board as claimed in claim 3, it is characterised in that：The defect taxon is according to defect ratio Determine that current defect is in killer regions or ISO regions, and according in advance to killer regions to the comparison result of unit It is defined with the defects of ISO regions, it is critical defect or non-lethal defect to determine current defect.

5. a kind of Defect Scanning board as claimed in claim 4, it is characterised in that：The defect taxon is tied according to classification Fruit generates defect report and is exported.

6. a kind of the defects of Defect Scanning board automatic classification method, includes the following steps：

Step 1 adds in GDS database, and defined in database not in the Defect Scanning board the defects of in scanning machine system Same region defines different type defect according to different zones；

Step 2 scans target wafer to capture defect

Step 3, the defects of being captured in real time in scanning process, are compared in the GDS database；

Step 4, the region according to residing for the comparison result of step 3 determines defect, and then determine corresponding area according to pre-defined The defects of domain, type was to realize the automatic classification of defect.

7. a kind of the defects of Defect Scanning board as claimed in claim 6 automatic classification method, it is characterised in that：In step 1 In, the killer regions defined in the GDS database and ISO regions, and the defects of killer regions, is defined into critical defect, The defects of ISO regions, is defined as non-lethal defect.

8. a kind of the defects of Defect Scanning board as claimed in claim 7 automatic classification method, it is characterised in that：In step 1 In, graphics field is defined as by killer regions by the form of scanning or setting coordinate, non-graphic region is defined as ISO areas Domain.

9. a kind of the defects of Defect Scanning board as claimed in claim 8 automatic classification method, it is characterised in that：In step 4 In, determine that current defect is in killer regions or ISO regions, and according to right in advance according to the comparison result of step 3 The defects of killer regions and ISO regions, defines, and it is critical defect or non-lethal defect to determine current defect.

10. a kind of the defects of Defect Scanning board as claimed in claim 9 automatic classification method, it is characterised in that：In step In four, generate defect report also according to classification results and exported.